IMO, I would recommend you to support both Firefox and Chrome.
Let me give you an example, I had never heard of Polarr Editor. Then one fine day as I browsed the Chrome store I found it to be pretty good. It even has a web version for both Chrome and Firefox. But it lacks so much exposure.
Same goes for webflow.
Why lose consumers?
Conclusion, There are some Apps in the Chrome web store exclusive to Chrome that suffer from the inexposure to Firefox.
Most developers use both Chrome and FF alternatively as they wish. And FF's share of users is more tech oriented.
1% of web browser share equivalents around 1 million users or more.
Now, the math is self-explanatory.
Hope it helps.